The Hive wasn't worried about God's Left Hand's offer. The negotiations for the surrender of the Shandal Empire didn't allow it to attack any of the invaders. Also, it limited the influence that it could have on the political environment of the world.
The invaders had cut it off from any event, allowing it to survive only inside the blue dome and in the wrecked regions around it.
That wasn't an ideal solution for the Empire, but preventing its destruction was already an outstanding achievement. The blue dome had even allowed it to retain many powerful assets and resources, making its situation less dramatic than it looked.
Noah and the Demons discussed God's Left Hand's offer in private. Chasing Demon had already agreed to send them in the blue dome to see what the Empire could give them, but the trio wanted to set their story straight first.